package com.hmdp.utils;

import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

@Component
public class RedisIdWorker {
    /*
    * 开始时间戳
    * */
    private static final long BEGIN_TIMESTAMP = 1672531200;
    /*
    * 序列号的位数
    * */
    private static final int COUNT_BITS = 32;

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    public long nextId(String keyPrefix){
        //1、生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long newSecond = now.toEpochSecond(ZoneOffset.UTC);
        long timeTamp = newSecond - BEGIN_TIMESTAMP;
        //2、生成序列号
        //2.2.获取当前日期，精确到天
        String date = now.format(DateTimeFormatter.ofPattern("yyyyMMdd"));
        //2.2.自增长
        Long count = stringRedisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" + date);

        //3、拼接并返回
        return timeTamp << COUNT_BITS | count;
    }

    public static void main(String[] args) {
        LocalDateTime time = LocalDateTime.of(2023, 1, 1, 0, 0, 0);
        long second = time.toEpochSecond(ZoneOffset.UTC);
        System.out.println("second = " + second);
    }
}
